Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers
Interactions between injected CO2, brine, and rock during CO2 sequestration in deep saline aquifers alter their natural hydro-mechanical properties, affecting the safety, and efficiency of the sequestration process. This study aims to identify such interaction-induced mineralogical changes in aquife...
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ftpubmed:oai:pubmedcentral.nih.gov:4726200 2023-05-15T15:52:45+02:00 Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers Rathnaweera, T. D. Ranjith, P. G. Perera, M. S. A. 2016-01-20 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4726200/ http://www.ncbi.nlm.nih.gov/pubmed/26785912 https://doi.org/10.1038/srep19362 en eng Nature Publishing Group http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4726200/ http://www.ncbi.nlm.nih.gov/pubmed/26785912 http://dx.doi.org/10.1038/srep19362 Copyright © 2016, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ CC-BY Article Text 2016 ftpubmed https://doi.org/10.1038/srep19362 2016-01-31T01:23:07Z Interactions between injected CO2, brine, and rock during CO2 sequestration in deep saline aquifers alter their natural hydro-mechanical properties, affecting the safety, and efficiency of the sequestration process. This study aims to identify such interaction-induced mineralogical changes in aquifers, and in particular their impact on the reservoir rock’s flow characteristics. Sandstone samples were first exposed for 1.5 years to a mixture of brine and super-critical CO2 (scCO2), then tested to determine their altered geochemical and mineralogical properties. Changes caused uniquely by CO2 were identified by comparison with samples exposed over a similar period to either plain brine or brine saturated with N2. The results show that long-term reaction with CO2 causes a significant pH drop in the saline pore fluid, clearly due to carbonic acid (as dissolved CO2) in the brine. Free H+ ions released into the pore fluid alter the mineralogical structure of the rock formation, through the dissolution of minerals such as calcite, siderite, barite, and quartz. Long-term CO2 injection also creates a significant CO2 drying-out effect and crystals of salt (NaCl) precipitate in the system, further changing the pore structure. Such mineralogical alterations significantly affect the saline aquifer’s permeability, with important practical consequences for the sequestration process. Text Carbonic acid PubMed Central (PMC) Scientific Reports 6 1 |
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Article Rathnaweera, T. D. Ranjith, P. G. Perera, M. S. A. Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers |
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Article |
description |
Interactions between injected CO2, brine, and rock during CO2 sequestration in deep saline aquifers alter their natural hydro-mechanical properties, affecting the safety, and efficiency of the sequestration process. This study aims to identify such interaction-induced mineralogical changes in aquifers, and in particular their impact on the reservoir rock’s flow characteristics. Sandstone samples were first exposed for 1.5 years to a mixture of brine and super-critical CO2 (scCO2), then tested to determine their altered geochemical and mineralogical properties. Changes caused uniquely by CO2 were identified by comparison with samples exposed over a similar period to either plain brine or brine saturated with N2. The results show that long-term reaction with CO2 causes a significant pH drop in the saline pore fluid, clearly due to carbonic acid (as dissolved CO2) in the brine. Free H+ ions released into the pore fluid alter the mineralogical structure of the rock formation, through the dissolution of minerals such as calcite, siderite, barite, and quartz. Long-term CO2 injection also creates a significant CO2 drying-out effect and crystals of salt (NaCl) precipitate in the system, further changing the pore structure. Such mineralogical alterations significantly affect the saline aquifer’s permeability, with important practical consequences for the sequestration process. |
format |
Text |
author |
Rathnaweera, T. D. Ranjith, P. G. Perera, M. S. A. |
author_facet |
Rathnaweera, T. D. Ranjith, P. G. Perera, M. S. A. |
author_sort |
Rathnaweera, T. D. |
title |
Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers |
title_short |
Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers |
title_full |
Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers |
title_fullStr |
Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers |
title_full_unstemmed |
Experimental investigation of geochemical and mineralogical effects of CO2 sequestration on flow characteristics of reservoir rock in deep saline aquifers |
title_sort |
experimental investigation of geochemical and mineralogical effects of co2 sequestration on flow characteristics of reservoir rock in deep saline aquifers |
publisher |
Nature Publishing Group |
publishDate |
2016 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4726200/ http://www.ncbi.nlm.nih.gov/pubmed/26785912 https://doi.org/10.1038/srep19362 |
genre |
Carbonic acid |
genre_facet |
Carbonic acid |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4726200/ http://www.ncbi.nlm.nih.gov/pubmed/26785912 http://dx.doi.org/10.1038/srep19362 |
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Copyright © 2016, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
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CC-BY |
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https://doi.org/10.1038/srep19362 |
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Scientific Reports |
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